More than 1,000 people gathered in Tripoli on Friday to denounce Libya's military strongman Khalifa Haftar's offensive.Protesters say they will return every week until Haftar's forces withdraw.The United Nations-backed government accuses Haftar's forces of using heavy weapons in populated areas.Indiscriminate shelling has killed many civilians and forced thousands to leave their homes.Al Jazeera's Mahmoud Abdelwahed reports.